A cleaning method for a semiconductor process apparatus

Abstract

The application provides a cleaning method of a semiconductor process equipment, and relates to the technical field of semiconductors.The cleaning method comprises the following steps: dividing deposits in a process chamber into different types, and obtaining film thicknesses of the deposits of each type; determining cleaning gas and process parameters of N cleaning stages according to the types of the deposits and the corresponding film thicknesses, wherein each cleaning stage is configured to remove one type of the deposits, and the process parameters comprise chamber temperature, chamber pressure, flow rate of the cleaning gas and process time; and sequentially performing the N cleaning stages to sequentially remove the deposits of the corresponding types.The cleaning method sets multiple cleaning stages in cooperation, efficiently and completely removes different types of deposits in sequence, does not depend on the exhaust structure of the semiconductor process equipment, can ensure the vertical uniformity of the cleaning effect, and effectively improves the removal efficiency and effect of the deposits in the process chamber.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a method for cleaning semiconductor process equipment. Background Technology

[0002] Thin film deposition is crucial in semiconductor device fabrication. For example, ALD (Atomic Layer Deposition) is widely used for depositing films such as silicon oxide, nitrides, and polycrystalline silicon. Thin film deposition typically uses a vertical furnace as the process equipment. During the process, deposits form on the walls of the process chamber. Dry cleaning is the core step for removing residual precursors, byproducts, and particulate matter from the process chamber, directly affecting film uniformity and equipment stability. Compared to traditional wet cleaning, dry cleaning reduces secondary contamination caused by residual chemical reagents and is irreplaceable for processing high-selectivity films. Furthermore, the fact that dry cleaning does not require disassembling the furnace tubes significantly reduces equipment maintenance time.

[0003] However, in related technologies, dry cleaning of semiconductor process equipment suffers from poor vertical uniformity and long cleaning time, resulting in poor effectiveness and efficiency of dry cleaning. Summary of the Invention

[0004] The purpose of this invention is to provide a cleaning method for semiconductor process equipment, so as to solve the technical problem that the dry cleaning of semiconductor process equipment has poor effect and efficiency in related technologies.

[0005] To address the above problems, the present invention provides a cleaning method for semiconductor process equipment, comprising:

[0006] The deposits in the process chamber were classified into different types, and the film thickness of each type of deposit was obtained;

[0007] The cleaning gases and process parameters for N cleaning stages are determined based on the type of deposit and the corresponding film thickness, wherein each cleaning stage is configured to remove one type of deposit, and the process parameters include chamber temperature, chamber pressure, cleaning gas flow rate and process time.

[0008] The cleaning stages are executed sequentially N times to remove the corresponding types of deposits in sequence.

[0009] Optionally, the step of determining the cleaning gas and process parameters for N cleaning stages based on the type of deposit and the corresponding film thickness includes:

[0010] The cleaning gas, chamber temperature, and chamber pressure for N cleaning stages are determined based on the type of deposit.

[0011] The flow rate of the cleaning gas and the process time are determined based on the reaction rate of the cleaning gas with the corresponding type of deposit at the chamber temperature and chamber pressure, as well as the film thickness of the corresponding type of deposit in each cleaning stage.

[0012] Optionally, the cleaning stage sequentially includes a vacuuming step of evacuating the process chamber, a cleaning step of introducing cleaning gas into the process chamber, and a purging step of introducing purging gas into the process chamber; the process parameters also include the number of cycles.

[0013] The step of sequentially executing N cleaning stages includes:

[0014] Sort the execution order of the N cleaning stages;

[0015] Each cleaning phase is executed in sequence, and the next cleaning phase is only executed after each cleaning phase has been executed a certain number of times.

[0016] Optionally, the deposits in the process chamber are classified into metal deposits and non-metal deposits. The cleaning stage corresponding to the metal deposits is designated as the first cleaning stage, and the cleaning stage corresponding to the non-metal deposits is designated as the second cleaning stage. The cleaning gas in the first cleaning stage and the cleaning gas in the second cleaning stage are both fluorine-containing gases, and the flow rate of the cleaning gas in the first cleaning stage is less than the flow rate of the cleaning gas in the second cleaning stage.

[0017] Optionally, the cleaning gas in the first cleaning stage includes ClF3, the flow rate of the cleaning gas is 500-1000 sccm, the chamber temperature is 200-400℃, and the chamber pressure is 50-400 Torr.

[0018] Optionally, the non-metallic deposit is a silicon-based deposit, and the cleaning gas in the second cleaning stage includes NF3, with a flow rate of 1000–8000 sccm, a chamber temperature of 200–400°C, and a chamber pressure of 50–400 Torr.

[0019] Optionally, the cleaning method further includes:

[0020] The incorporation gas for the second cleaning stage is determined based on the type of silicon-based deposit.

[0021] Optionally, the cleaning method further includes:

[0022] The cleaning gas and process parameters for the post-treatment stage are determined based on the cleaning gas and process parameters of the N cleaning stages.

[0023] After sequentially executing N cleaning stages, the post-processing stage is then executed to remove halogen residues introduced by the N cleaning stages.

[0024] Optionally, the cleaning gas in the post-treatment stage includes Ar and H2, and the flow ratio of Ar to H2 ranges from 5:1 to 3:1.

[0025] Optionally, when at least one of the cleaning stages introduces a cleaning gas into the process chamber, radio frequency power is applied to the cleaning gas to excite it into plasma.

[0026] The cleaning method for semiconductor process equipment provided by this invention classifies deposits formed in the process chamber into N different types based on their composition and reaction properties, and obtains the film thickness of each type of deposit. Then, different cleaning stages are used to sequentially clean the different types of deposits. The cleaning gas used in each cleaning stage has a high selectivity for the corresponding type of deposit, ensuring thorough removal of deposits in all vertical areas of the process chamber even under the limitation of a single air intake direction. Simultaneously, the chamber temperature and pressure determined for each cleaning stage ensure efficient reaction between the cleaning gas and the deposits. Furthermore, the flow rate and process time determined for each cleaning stage ensure thorough removal of deposits by the cleaning gas, reducing excessive cleaning damage to the inner wall of the process chamber caused by excessively long process times and ineffective waste of cleaning gas. Accordingly, multiple cleaning stages work together to efficiently and thoroughly remove different types of deposits sequentially. This method is less limited by a single air intake direction, does not rely on the intake and exhaust structure of the semiconductor process equipment, ensures vertical uniformity of the cleaning effect, and effectively improves the removal efficiency and effectiveness of deposits in the process chamber. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a flowchart illustrating a method for cleaning semiconductor process equipment in related technologies.

[0029] Figure 2 This is a first process diagram of a cleaning method for semiconductor process equipment provided according to an embodiment of the present invention;

[0030] Figure 3This is a second process diagram of a cleaning method for semiconductor process equipment provided according to an embodiment of the present invention;

[0031] Figure 4 This is a partial process diagram of a cleaning method for semiconductor process equipment provided according to an embodiment of the present invention. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Figure 1 This is a flowchart illustrating a method for cleaning semiconductor process equipment in related technologies.

[0036] Among the technologies related to cleaning semiconductor process equipment, such as Figure 1As shown, based on different operating temperatures, the working components of the furnace tube in the semiconductor process equipment are divided into a first component group at a lower operating temperature and a second component group (quartz tube and quartz boat) at a higher operating temperature. The first component group is then heated to a lower first temperature, and hydrogen fluoride is introduced into the furnace tube to remove the silicon dioxide film on its working surface. Subsequently, the second component group is heated to a higher second temperature, and fluoride gas is introduced into the furnace tube to remove the silicon dioxide film on its working surface. However, the deposits formed on the furnace tube working surface during the process are not of a single type. For example, in addition to deposits introduced by thin film deposition, deposits can also be introduced by the piping and mechanical transmission equipment of the semiconductor process equipment. In related technologies, only a single cleaning gas is used to clean the working surface of a single component group, resulting in low cleaning efficiency and the inability to completely remove deposits. Especially for the taller second component group, a single gas inlet direction leads to uneven cleaning of the furnace tube working surface in the vertical direction, causing insufficient cleaning and deposit residue in areas far from the gas inlet within the furnace tube.

[0037] This invention provides a cleaning method for semiconductor process equipment. Based on the reaction properties, deposits formed within the process chamber are classified into different types, and the film thickness of each type of deposit is obtained. Then, different cleaning stages are used to sequentially clean the different types of deposits. The cleaning gas used in each cleaning stage has a high selectivity for the corresponding type of deposit, enabling thorough removal of deposits in all vertical regions of the process chamber even under the limitation of a single air intake direction. Simultaneously, the chamber temperature and pressure determined for each cleaning stage are suitable for efficient reaction between the corresponding cleaning gas and the deposits. Furthermore, the flow rate and process time of the cleaning gas determined for each cleaning stage ensure complete removal of the deposits by the corresponding cleaning gas, reducing excessive cleaning damage to the inner wall of the process chamber caused by excessively long process times and ineffective waste of cleaning gas. Accordingly, multiple cleaning stages work together to efficiently and thoroughly remove deposits within the process chamber. For ease of understanding, the technical solutions disclosed in various embodiments of this invention are described in detail below with reference to the accompanying drawings.

[0038] Figure 2 This is a schematic diagram of the first process of a cleaning method for semiconductor process equipment provided according to an embodiment of the present invention. Figure 2 As shown, the cleaning method includes the following steps:

[0039] S202 classifies the deposits in the process chamber into different types and obtains the film thickness of each type of deposit.

[0040] S204 determines the cleaning gas and process parameters for N cleaning stages based on the type of deposit and the corresponding film thickness. Each cleaning stage is configured to remove one type of deposit, and the process parameters include chamber temperature, chamber pressure, cleaning gas flow rate, and process time.

[0041] Based on the composition and reaction properties of the sediments, they are divided into N different types, and the film thickness of each type of sediment is obtained; where N is an integer greater than 1.

[0042] The cleaning gas in the cleaning stage determines the etching selectivity of the corresponding deposits, that is, the selective removal effect of the cleaning gas on the corresponding deposits; the chamber temperature and chamber pressure in the process parameters determine the intensity of the reaction between the cleaning gas and the corresponding deposits, that is, the removal efficiency of the cleaning gas on the corresponding deposits; the flow rate and process time in the process parameters determine the reaction rate and reaction amount between the cleaning gas and the corresponding deposits, that is, the removal amount of the cleaning gas on the corresponding deposits.

[0043] Based on the type of deposit and the film thickness of each type of deposit, determine the cleaning gas and process parameters such as chamber temperature, chamber pressure, cleaning gas flow rate, and process time for N cleaning stages. This will ensure that the cleaning gas in each cleaning stage can efficiently and thoroughly remove the corresponding type of deposit, and reduce the adverse effects of excessively long cleaning gas ventilation time on the inner wall of the process chamber, the waste of cleaning gas, and the reduction in cleaning efficiency.

[0044] S206 sequentially executes N cleaning stages to remove the corresponding types of deposits in sequence.

[0045] According to the determined cleaning gas and process parameters for N cleaning stages, each cleaning stage is executed sequentially. Specifically, the first cleaning stage is executed first, adjusting the chamber temperature and pressure of the process chamber to the determined chamber temperature and pressure; then, a determined flow rate of cleaning gas is introduced into the process chamber. The cleaning gas reacts efficiently with the first type of deposits to remove them. When the cleaning gas has completely removed the first type of deposits, the determined process time is reached, and the supply of cleaning gas into the process chamber is stopped, completing the complete removal of the first type of deposits in the first cleaning stage; similarly, the second cleaning stage...the Nth cleaning stage is executed sequentially, correspondingly completing the complete removal of the second type of deposits...the Nth type of deposits in sequence.

[0046] In summary, the semiconductor process equipment cleaning method provided by this invention classifies deposits formed in the process chamber into N different types based on their composition and reaction properties, and obtains the film thickness of each type of deposit. Then, different cleaning stages are used to sequentially clean the different types of deposits. The cleaning gas used in each cleaning stage has a high selectivity for the corresponding type of deposit, ensuring thorough removal of deposits in all vertical areas of the process chamber even under the limitation of a single air intake direction. Simultaneously, the chamber temperature and pressure determined for each cleaning stage ensure efficient reaction between the cleaning gas and the deposits. Furthermore, the flow rate and process time of the cleaning gas determined for each cleaning stage ensure thorough removal of the deposits by the cleaning gas, reducing excessive cleaning damage to the inner wall of the process chamber caused by excessively long process times and ineffective waste of cleaning gas. Accordingly, multiple cleaning stages work together to efficiently and thoroughly remove different types of deposits sequentially. This method is less limited by a single air intake direction, does not rely on the intake and exhaust structure of the semiconductor process equipment, ensures vertical uniformity of the cleaning effect, and effectively improves the removal efficiency and effectiveness of deposits in the process chamber.

[0047] Specifically, semiconductor process equipment can be a vertical furnace.

[0048] In this embodiment of the invention, step S204, which involves determining the cleaning gas and process parameters for N cleaning stages based on the type of deposit and the corresponding film thickness, includes: determining the cleaning gas, chamber temperature, and chamber pressure for N cleaning stages based on the type of deposit; and determining the flow rate and process time of the cleaning gas based on the reaction rate of the cleaning gas with the corresponding type of deposit at the chamber temperature and chamber pressure, as well as the film thickness of the corresponding type of deposit.

[0049] The type of sediment can characterize its composition and reaction properties. Based on the sediment type, a cleaning gas with a high etching selectivity is selected as the cleaning gas for the corresponding cleaning stage. Then, based on suitable reaction conditions between the sediment and the selected cleaning gas, the chamber temperature and pressure for the corresponding cleaning stage are determined to ensure efficient reaction between the sediment and the cleaning gas, and consequently, efficient removal of the corresponding type of sediment by the cleaning gas. The sediment film thickness characterizes the amount of sediment to be removed, and the cleaning gas flow rate determines the removal rate of the sediment by the cleaning gas. Process time and cleaning gas flow rate together determine the total amount of sediment removed by the cleaning gas. Based on the film thickness of the corresponding type of sediment and the removal rate of the sediment by the cleaning gas, an appropriate cleaning gas flow rate and process time are determined to ensure that the cleaning gas can completely remove the corresponding type of sediment within the process time. This allows for precise control of the effective removal of the corresponding type of sediment in the cleaning stage, avoiding situations where insufficient cleaning gas flow leads to sediment residue, or excessive cleaning gas flow causes excessive etching damage to the inner wall of the process chamber and results in a longer process time.

[0050] By sequentially determining the cleaning gas and process parameters for N cleaning stages, and coordinating these N cleaning stages, the corresponding types of deposits can be removed efficiently and thoroughly. This method is less restricted by a single air intake direction, ensures the vertical uniformity of the cleaning effect, and effectively improves the removal efficiency and effectiveness of deposits in the process chamber.

[0051] In this embodiment of the invention, the cleaning stage sequentially includes a vacuuming step of evacuating the process chamber, a cleaning step of introducing cleaning gas into the process chamber, and a purging step of introducing purging gas into the process chamber; the process parameters also include the number of cycles; step S206: the step of sequentially executing N cleaning stages includes: sorting the execution order of the N cleaning stages; executing each cleaning stage according to the sorting, and only continuing to execute the next cleaning stage after the number of cycles of each cleaning stage reaches the corresponding number of cycles.

[0052] Each cleaning stage includes a vacuuming step, a cleaning step, and a purging step. The vacuuming step removes residual gas, particulate matter, and precursors from the process chamber to ensure vacuum and cleanliness, thus guaranteeing effective reaction between the cleaning gas and deposits in subsequent cleaning steps. The cleaning step introduces cleaning gas into the process chamber to react with and efficiently remove the corresponding type of deposits. The purging step introduces purging gas into the process chamber to purge the cleaning gas and deposit products, as well as residual gas, from the process chamber, reducing the adverse effects of residues on the effective reaction between the cleaning gas and deposits. Specifically, the purging gas can be an inert gas. Dividing each cleaning stage into multiple small cycles consisting of vacuuming, cleaning, and purging steps improves the removal efficiency of the cleaning gas on deposits, thereby increasing the removal efficiency of each cleaning stage for the corresponding type of deposit, and further improving the overall removal efficiency of the cleaning method provided in this embodiment for deposits within the process chamber.

[0053] The process time specifically includes the evacuation time of the evacuation step, the cleaning time of the cleaning step, the purging time of the purging step, the interval between the evacuation and cleaning steps, and the interval between the cleaning and purging steps. After determining the required total cleaning time based on the film thickness of the deposit, the flow rate of the cleaning gas, and the reaction rate between the cleaning gas and the corresponding type of deposit, a positive integer that is close to or not less than the ratio of the total cleaning time to the cleaning time of a single cleaning step can be used as the number of cycles. Based on the flow rate of the cleaning gas and the cleaning time of a single cleaning step, the purging time of the purging step and the evacuation time of the evacuation step can be determined, and the interval between two adjacent steps can be reasonably determined, thereby determining the process time.

[0054] During the process, a single cleaning stage consists of a small cycle consisting of an extraction step, a cleaning step, and a purging step. When the total time reaches the predetermined process time or the number of cycles reaches the predetermined number of cycles, the cleaning stage is stopped, and the next cleaning stage continues in a predetermined order.

[0055] In this embodiment of the invention, the cleaning method further includes: determining the cleaning gas and process parameters of the post-treatment stage based on the cleaning gas and process parameters of the N cleaning stages; and continuing to execute the post-treatment stage after sequentially executing the N cleaning stages to remove the halogen residues generated in the N cleaning stages. The cleaning gases in the N cleaning stages generally include halogen elements. During the process of removing deposits by reacting with the cleaning gases, intermediate or final products containing halogen elements may remain in the process chamber, causing etching damage to the inner wall of the process chamber and the wafer. The type of halogen residue can be determined based on the type of cleaning gases in the N cleaning stages. Cleaning gases that can effectively remove halogen residues without introducing new halogen residues are selected as the cleaning gases for the post-processing stages. The amount of halogen residues can be determined based on the process parameters of the N cleaning stages. The process parameters of the cleaning gases are determined based on the amount of halogen residues and the reaction rate between the cleaning gases and halogen residues in the post-processing stages. This ensures that the post-processing stages efficiently and thoroughly remove halogen residues from the process chamber, reducing the occurrence of insufficient cleaning gas supply leading to halogen residues or excessive supply leading to wasted cleaning gas, as well as long processing times and low efficiency.

[0056] After N cleaning stages are completed, a post-processing stage is performed to effectively and thoroughly remove the halogens introduced in the N cleaning stages, reduce the damage caused by halogen residues to the inner wall of the process chamber and the wafer, and thus ensure the accuracy and yield of the wafer deposition process.

[0057] Specifically, in this embodiment of the invention, the post-treatment stage may also include a vacuuming step of evacuating the process chamber, a cleaning step of introducing cleaning gas into the process chamber, and a purging step of introducing purging gas into the process chamber. The process parameters include chamber temperature, chamber pressure, cleaning gas flow rate, and process time. The process time specifically includes the vacuuming time of the vacuuming step, the cleaning time of the cleaning step, the purging time of the purging step, the interval between the vacuuming and cleaning steps, and the interval between the cleaning and purging steps. Dividing the post-treatment stage into multiple small cycles consisting of vacuuming, cleaning, and purging steps improves the removal efficiency of halogen residues by the cleaning gas while ensuring the removal effect of deposits in the process chamber.

[0058] In this embodiment of the invention, the cleaning gas in the post-processing stage includes Ar and H2, and the flow ratio of Ar to H2 is in the range of 5:1 to 3:1, so as to effectively reduce halogen residues in the process chamber, improve the cleanliness of the process chamber and the quality of the film layer in subsequent wafer deposition.

[0059] Specifically, the purging steps in the pre-cleaning stage, main cleaning stage, and post-treatment stage all use inert gas for purging.

[0060] In this embodiment of the invention, the deposits in the process chamber are classified into metallic deposits and non-metallic deposits. The cleaning stage corresponding to metallic deposits is designated as the first cleaning stage, and the cleaning stage corresponding to non-metallic deposits is designated as the second cleaning stage. Both the cleaning gas in the first and second cleaning stages are fluorine-containing gases, and the flow rate of the cleaning gas in the first cleaning stage is less than that in the second cleaning stage. Specifically, the deposits are classified into metallic deposits and non-metallic deposits. Metallic deposits are mainly introduced during the process from furnace tubes and mechanical transmission structures of semiconductor process equipment, and mainly include Al2O3, Fe2O3, and CuO. Non-metallic deposits are mainly introduced during the thin film deposition process and mainly include Si3N4 and SiO2. Fluorine-containing gases include HF, F2, NF3, and ClF3.

[0061] Non-metallic deposits are the main type of deposits. Therefore, it was determined that metallic deposits should be removed first, with the first cleaning stage serving as the pre-cleaning stage. Non-metallic deposits should then be removed, with the second cleaning stage serving as the main cleaning stage. This approach aims to minimize the obstruction caused by metallic deposits to the removal of non-metallic deposits. Both the cleaning gas used in the first cleaning stage (for metallic deposits) and the cleaning gas used in the second cleaning stage (for non-metallic deposits) are fluorine-containing gases. The flow rate of the cleaning gas in the second cleaning stage is determined to be larger based on the film thickness of both metallic and non-metallic deposits, thereby improving the removal efficiency of non-metallic deposits in the second cleaning stage and reducing the time required.

[0062] Specifically, the type of deposit can be entered or recorded by the operator. The film thickness of non-metallic deposits is automatically recorded during thin film deposition in semiconductor process equipment, while metallic deposits are reflected in the metal test of the test wafer in the furnace.

[0063] Specifically, in this embodiment of the invention, the cleaning gas in the first cleaning stage includes ClF3, with a flow rate of 500–1000 sccm, a chamber temperature of 200–400°C, and a chamber pressure of 50–400 Torr. ClF3, which is relatively effective at etching metal deposits and is also more environmentally friendly, was chosen as the cleaning gas for the first cleaning stage to effectively remove metal deposits. The etching rate of ClF3 can reach 10 μm / min. The chamber temperature is set to 200–400°C to reduce the deposition of reaction products on the pipelines and pump lines. Specifically, the relevant reaction chemical formula is:

[0064] Al2O3+6ClF3→2AlF3+3Cl2+3O2;

[0065] Fe2O3+6ClF3→2FeF3+3Cl2+3O2;

[0066] CuO + 2ClF3 → CuF2 + Cl2 + O2.

[0067] Specifically, in this embodiment of the invention, the non-metallic deposit is a silicon-based deposit. The cleaning gas in the second cleaning stage includes NF3, with a flow rate of 1000–8000 sccm, a chamber temperature of 200–400°C, and a chamber pressure of 50–400 Torr. NF3, which exhibits high selectivity for etching non-metallic deposits and a superior etching selectivity ratio, is selected as the cleaning gas for the second cleaning stage to effectively remove non-metallic deposits and maximize etching selectivity, thereby improving the vertical uniformity of the cleaning effect in the process chamber. Specifically, the relevant reaction chemical formulas are:

[0068] 12NF3 + Si3N4 → 3SiF4 + 6N2;

[0069] 6NF3 + SiO2 → SiF4 + 3N2.

[0070] In this embodiment of the invention, the cleaning method further includes: determining the doping gas for the second cleaning stage based on the type of silicon-based deposit. Incorporating the cleaning gas in the second cleaning stage effectively improves the etching selectivity of the cleaning gas for the silicon-based deposit, thereby further enhancing the efficiency and thoroughness of the cleaning gas in removing non-metallic deposits within the process chamber.

[0071] Specifically, when the silicon-based deposit is Si3N4, hydrogen-containing gases, such as H2, can be incorporated into NF3 to improve its etching selectivity for Si3N4, thereby enhancing the removal effect and efficiency of Si3N4 and reducing excessive etching damage to the quartz furnace tube caused by the cleaning gas. Depending on the specific type of silicon-based deposit, doping gases such as NO and O2 can also be incorporated into NF3.

[0072] In this embodiment of the invention, when cleaning gas is introduced into the process chamber during at least one cleaning stage, radio frequency power is applied to the cleaning gas via a radio frequency generator to excite it into plasma. The cleaning gas introduced into the process chamber can become plasma containing active free radicals under the excitation of radio frequency power. This plasma exhibits higher reaction and removal efficiency and better effect on metal and non-metal deposits, thereby further improving the cleaning effect and efficiency on the deposits. Specifically, radio frequency power is applied to the cleaning gas introduced into the process chamber during all cleaning stages to improve the cleaning effect and efficiency on the corresponding deposits in all cleaning stages.

[0073] Similarly, when the cleaning gas is introduced into the process chamber during the post-processing stage, radio frequency power is applied to the cleaning gas to excite it into plasma, thereby improving the cleaning effect and efficiency of the cleaning gas on halogen residues.

[0074] Specifically, the radio frequency power is 100-300W and the radio frequency is 12-14MHz. For cases where the deposits are metallic or non-metallic, the cleaning method provided in this embodiment can shorten the cleaning time by 20%-40% compared to traditional methods.

[0075] Figure 3 This is a schematic diagram of the second process of a cleaning method for semiconductor process equipment provided according to an embodiment of the present invention. Figure 3 As shown, the cleaning method includes:

[0076] S301 classifies the deposits in the process chamber into different types and obtains the film thickness of each type of deposit.

[0077] S302 determines the cleaning gas, chamber temperature, and chamber pressure for N cleaning stages based on the type of sediment.

[0078] S303 determines the flow rate and process time of the cleaning gas based on the reaction rate of the cleaning gas with the corresponding type of deposit under the chamber temperature and pressure, as well as the film thickness of the corresponding type of deposit in each cleaning stage.

[0079] S304 determines the cleaning gas and process parameters for the post-treatment stage based on the cleaning gases and process parameters of the N cleaning stages.

[0080] S305 sorts the execution order of the N cleaning stages.

[0081] S306 performs each cleaning stage in sequence to remove the corresponding type of deposits in turn.

[0082] S307 performs a post-processing phase to remove halogen residues generated in the N cleaning phases.

[0083] Figure 4 This is a partial flow diagram of a cleaning method for semiconductor process equipment provided according to an embodiment of the present invention. When the deposit type includes metal deposits and non-metal deposits, there are two cleaning stages. The cleaning stage for removing metal deposits is the pre-cleaning stage, and the cleaning stage for removing non-metal deposits is the main cleaning stage. After the two cleaning stages are completed, a post-processing stage is performed. The pre-cleaning stage, the main cleaning stage, and the post-processing stage all include an air extraction step, a cleaning step, and a purging step. The specific execution flow of the pre-cleaning stage, the main cleaning stage, and the post-processing stage is as follows: Figure 4 As shown:

[0084] S401 enters the pre-cleaning stage.

[0085] S4011 performs vacuuming of the process chamber.

[0086] S4012 pulses FCl3 into the process chamber to decompose the metal deposits.

[0087] S4013 introduces inert gas into the process chamber for purging.

[0088] S4014 determines whether the pre-cleaning stage cycle has been reached. If yes, proceed to step S402; otherwise, continue to step S4011.

[0089] S402 enters the main cleaning phase.

[0090] S4021 performs vacuuming of the process chamber.

[0091] S4022 pulses NF3 into the process chamber to decompose non-metallic deposits.

[0092] S4023 introduces inert gas into the process chamber for purging.

[0093] S4024 Determine whether the required number of cycles for the main cleaning phase has been reached. If yes, proceed to step S403; otherwise, continue to step S4021.

[0094] S403 enters the post-processing stage.

[0095] S4031 performs vacuuming of the process chamber.

[0096] S4032 pulses Ar / H2 mixed cleaning gas into the process chamber to remove halogen residues.

[0097] S4033 introduces inert gas into the process chamber for purging.

[0098] S4034 determines whether the number of cycles for the post-processing stage has been reached. If yes, the cleaning process is completed; otherwise, step S4031 is executed.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cleaning semiconductor process equipment, characterized in that, include: The deposits in the process chamber are divided into N different types, and the film thickness of each type of deposit is obtained, where N is an integer greater than 1; N cleaning stages and process parameters are determined based on N types of deposits and their corresponding film thicknesses, wherein each cleaning stage is configured to remove one type of deposit, and the cleaning gas used in each cleaning stage has a high selectivity for the corresponding type of deposit; the process parameters include chamber temperature, chamber pressure, cleaning gas flow rate, and process time; the step of determining the cleaning gas and process parameters for the N cleaning stages based on the type of deposit and its corresponding film thickness includes: determining the cleaning gas, chamber temperature, and chamber pressure for the N cleaning stages based on the N types of deposits; determining the cleaning gas flow rate and process time based on the reaction rate of the cleaning gas with the corresponding type of deposit at the chamber temperature and chamber pressure, and the film thickness of the corresponding type of deposit, and the determined cleaning gas flow rate and process time for each cleaning stage can ensure complete removal of the deposit by the corresponding cleaning gas; The cleaning stages are executed sequentially N times to remove the corresponding types of deposits in sequence; The deposits in the process chamber are classified into metal deposits and non-metal deposits. The cleaning stage corresponding to the metal deposits is the first cleaning stage, and the cleaning stage corresponding to the non-metal deposits is the second cleaning stage. The cleaning gas in the first cleaning stage and the cleaning gas in the second cleaning stage are both fluorine-containing gases, and the flow rate of the cleaning gas in the first cleaning stage is less than the flow rate of the cleaning gas in the second cleaning stage.

2. The cleaning method according to claim 1, characterized in that, The cleaning stage includes, in sequence, a vacuuming step of evacuating the process chamber, a cleaning step of introducing cleaning gas into the process chamber, and a purging step of introducing purging gas into the process chamber. The process parameters also include the number of cycles; The step of sequentially executing N cleaning stages includes: Sort the execution order of the N cleaning stages; Each cleaning phase is executed in sequence, and the next cleaning phase is only executed after each cleaning phase has been executed a certain number of times.

3. The cleaning method according to claim 1, characterized in that, The cleaning gas in the first cleaning stage includes ClF3, the flow rate of the cleaning gas is 500~1000 sccm, the chamber temperature is 200~400℃, and the chamber pressure is 50~400 Torr.

4. The cleaning method according to claim 1, characterized in that, The non-metallic deposit is a silicon-based deposit. The cleaning gas in the second cleaning stage includes NF3, with a flow rate of 1000~8000 sccm, a chamber temperature of 200~400℃, and a chamber pressure of 50~400 Torr.

5. The cleaning method according to claim 4, characterized in that, The cleaning method further includes: The incorporation gas for the second cleaning stage is determined based on the type of silicon-based deposit.

6. The cleaning method according to claim 1 or 2, characterized in that, The cleaning method further includes: The cleaning gas and process parameters for the post-treatment stage are determined based on the cleaning gas and process parameters of the N cleaning stages. After sequentially executing N cleaning stages, the post-processing stage is then executed to remove halogen residues introduced by the N cleaning stages.

7. The cleaning method according to claim 6, characterized in that, The cleaning gas in the post-treatment stage includes Ar and H2, and the flow ratio of Ar to H2 ranges from 5:1 to 3:

1.

8. The cleaning method according to claim 1 or 2, characterized in that, When at least one of the cleaning stages introduces a cleaning gas into the process chamber, radio frequency power is applied to the cleaning gas to excite it into plasma.

Images